Granted Patent
Utility
US 4,266,939 · App. 06/045,522
Composition of 4-amino-4'-nitrostilbene-2,2'-disulphonic acid diazo compounds and coloring process
Inventors:
John D. Hildreth, Anton F. Tschopp, David G. Evans
Patented Case
View Patent ↗
Granted: May 12, 1981
Filed: Jun 4, 1979
Inventors
John D. Hildreth
Anton F. Tschopp
David G. Evans
Assignee (at issue)
Ciba-Geigy
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.